Endothermic gas generator



June 29, 1965 e. w. WARDWELL, JR 3,192,020

ENDOTHERMIC GAS GENERATOR 2 Sheets-Sheet 1 Filed May 4, 1962 INVENTOR June 1965 G. w. WARDWELL, JR 3,

ENDOTHERMIC GAS GENERATOR 2 Sheets-Sheet 2 Filed m 4, 1962 INVENTOR. Geo/ye W Wa/"dw 4% United States Patent The present invention relates to endothermic gas generators and is an improvement on US. Patent No. 2,802,725.

In 'said patent a reversible endothermic generator for 'end by a coil and which have their other ends connected to a valve whereby the direction of the gas being fed into the generator can be reversed in the catalyticchamhers. The reversal of the gas in the two straight chambers causes the chambers to be expanded or contracted and the coil permits the relative movement of the two chambers because of its resiliency. Further, the coil prevents the gas passing between two chambers from being cooled since the coil is located in the furnace and maintains the gas at its desired heat.

While such a generator functions satisfactorily, it has been found that particles of the catalytic agents in the chamber may pass into the coil and dog the coil. This prevents a proper flowof gas through the generator and, particularly, in the coil between the two catalytic chambers. Also, from a manufacturing standpoint the use of the coil, because of space limitations, has made the installation thereof more diihcult.

The present invention maintains the advantages of the reversibility of the flow of gas in the catalytic chamber without the problems heretofore encountered.

This is accomplished by using a substantially U-shaped catalytic chamber with the straight chambers forming the legs of the U and having the inner ends connected by a transverse section forming the bow of the U, preferably of a diameter substantially equal to the diameter of the legs. With this construction, the dangerof clogging by catalytic particles in the coil of smaller diameter is eliminated.

In order to permit the thus connected straight catalytic chambers to expand and contract, the present invention provides novel means for supporting the chambers and also novel means for connecting the ends of the chamber to the reversing valve through yieldable connectors so that expansion and contraction of the catalytic chambers due to the temperature of the gas therein can be accommodated without damage to the equipment as the direction of flow is reversed.

This is accomplished in one form of the invention by mounting the cooling coils of the heat exchangers rigidly on the catalytic chambers and by connecting the exhaust ends of the cooling coils to the system through flexible connectors; also, by connecting the coolant supply to the heat exchangers by flexible connectors, thus permitting the coils and their connected catalytic chambers to expand and contract, as the case may be, without damage to the equipment connected thereto.

In another form of the invention the coil of the heat exchanger unit is utilized to provide the yielding connection between the catalytic chamber and the reversing valve;

Other features and advantages of the invention will be apparent from the specification and claims when consid- 35192329 Patented June 29, 1965 FIG. 2 is a sectional view taken on the lines 22 of FIG. 1.

FIG. 3 shows a sectional view of another form of yieldable connection between the ends of the catalytic chamber and the reversing valve as formed by the heat exchangers.

As shown in the drawings the generator comprises a housing 19 having heat insulating and resistant refractory wall structure 11 and closure 11a forming an interior heating chamber 12. While gas or other means may be utilized to heat the heating chamber, in the illustrated form of the invention the heat is provided by suitable electric heaters indicated diagrammatically. at 13 and mounted on the walls of the chamber which maintain the heating chamber at the desired heat depending upon the volume of gas passing therethrough. Disposed within the container is a U-shaped catalytic chamber comprising two straight chambers 14, 15 forming the sides or legs of the U connected at their lower ends by a transverse chamber 16 forming the base of the U as shown in FIG. 1 and having a suitable catalyst C in ball or particle form disposed therein.

As indicated in FIGS. 1 and 2, the base of the U and the sides of the U are preferably of substantially the same diameter so that the gas will flow freely along one side of the U across the transverse bow of the U and along the other side of the U during the gas generating process.

In the form of the invention of FIG. 1, the base of the U is preferably formed with a fiat bottom surface 16a supported by refractory blocks 17 resting on the bottom of the heating chamber. The upper free ends of the sides of the U are connected to heat exchangers 13, l having coils 2b, 21 rigidly mounted therein.

In accordance with the present invention, means are provided in the form of a yieldable connection to a reversing valve 28 to accommodate the movement of the free ends of the straight-catalytic chambers in response ered in connection with the accompanying drawings in V to the expansion and contraction of the chambers as the hot and cold gas flows therethrough in response to the reversal of flow as will be explained. While expansion joints may be used, in the illustrated form of FIG. 1 the ends of the catalytic chambers are rigidly connected by pipes 22, 23 to the adjacent ends of the coils 20, 21. The other ends of the coils are connected by flexible connectors 24, 25 to sediment traps 26, 27 which traps are connected to the fOHT-WflY reversing valve 28. The reversing valve is also connected to a line 29 having a fire check 3%) therein to a source of gas supply 31 and air supply 32, each having suitable valves and gauges, through pump P and to an outlet line 33 to the furnace to be supplied with the generated gas (not shown).

It will be seen that by operating the valve 28 the mixture of air and gas can be fed to either catalytic chambet and the output of the other chamber can be cooled and fed to the furnace.

The heat exchangers are connected to a water supply line 34 through a reversing valve 35 and lines 36, 37. Lines as, 37 are connected to the inlet ports of the exchangers by flexible lines 38, 39. The outlet ports of the heat exchanger are connected by flexible lines 40, 41 to a drain line 52.

Preferably, the coils 28, 21 are of substantial length and are formed into a number of turns in compact relation so that the hot generated gas from the catalytic chamher will be retained in the exchanger a suflicient time to have its temperature reduced to an acceptable value. Further, baffies 43, 44 in the exchangers will insure that the water does not pass through the coils but rather will be directed around the coils to insure a required heat transfer.

the present invention provides a standard 45 secured to the top of the heat exchanger and having a plate 46 at its upper end provided with apertures 47, 48 for engaging pins 49, 50 on the exchanger and which will control the vertical movement of the heat exchangers during the expansion and contraction as noted above.

In the form of the invention shown in FIG. 3 the structure of the system is the same as FIG. 1, except for the heat exchangers and the connections thereto and only so much of the system as is different is shown in this figure. It will be seen that the end portions of the catalytic chambers 14, 15, which are mounted in the heating chamber 12 of the housing having the heat insulating and resistant refractory wall structure 11 and closure 11a, are connected by pipes 122, 123 and by means of elbow constructions 122a, 123a to the upper free ends of the coils 120, 121 disposed in the heat exchanger housings 118, 119. The lower ends of the coils are fixed to the housings and are connected by pipes 124, 125 to the valve for reversing the flow of gas in the catalytic chambers. The housings 118, 119 are secured to the top closure 11a by legs 113a, 11%. The heat exchanger housings are connected to the supply of water by pipes 136, 137 which enter into the bottom of the exchanger unit, and an outlet pipe 142 is connected to the upper end of each of the housings to drain ofli the water as it flows into the housing and upwardly through the coils of the heat exchanger. With this construction it will be seen that a yieldable connection is provided to permit the expansion and contraction of the chambers 14, 15 as previously explained. Such movement of the free ends of the chambers will cause the pipes 122, 123 to move up or down and the resiliency of the coils 125), 121 will provide a sufiicient yield to accommodate this movement without transmitting it to the heat exchanger housing and to the other elements of the system connected thereto.

Thus, it will be seen that the heat exchangers and the coils are compact and can be secured to the catalytic chambers at the factory and shipped as assembled without requiring a large and expensive shipping container and still are capable of permitting vertical movement with the expansion and contraction of the vertical legs of the catalytic chamber because of the flexible connectors.

In operation, with the valves 23 and 35 in the position shown in FIG. 1, gas and air are fed from supplies 31, 32 through control valves and gauges to pump P and from the pump the mixture passes through a line 29 to the four-way valve 28. The mixture then passes through a sediment trap 27 into the coil 21 of the heat exchanger 19 and into the catalytic chamber 15. It will be noted that the Water supply valve is in a position so that water is not supplied to the exchanger 19 through which the mixture passes and hence no cooling will take place. As the mixture passes through the chambers 15, 16 and 14 it will be heated and will emerge from chamber 14 as a hot generated gas. The hot gas will pass through line 22 into the other cooling coil 20. Since the coolant or water is flowing through the heat exchanger 18 because the valve 35 connects the source 34 to line 36, the generated gas will be cooled to the desired temperature. From the coil 20, the gas passes through the sediment trap 26, the four-way valve 28 to the line 33 leading to the furnace or other receiver (not shown). Under these conditions catalytic chamber 15 having the cool gases entering therein will tend to contract and shorten it while the chamber 14 having the hot gases issuing therefrom will become very hot and tend to expand and lengthen. The heat exchangers connected to the chambers 14, 15 will move with them and will be guided by guide plate 46 cooperating with guide pins 49, 50 in their vertical movement.

In the form of the invention shown in FIG. 3, the cool gas mixture is fed through the pipe 125 to the coil 121, through the coil to the pipe 123, into the catalytic chamber 15 and Will be heated and will emerge as an extremely hot gas from the end of the catalytic chamber 14. It will then pass through pipe 122, connector 122a and through the coil 129 to the pipe 124 leading to the reversing valve and to the furnace or other device to use the gas. Coolant, such as water, will pass along pipe 136 to the heat exchanger unit 118 and will move upwardly around the coil and out the drain 142.

In each form of the invention, after a predetermined period of operation, the four-way valve is reversed and the water supply valve is reversed, thus sending the cool mixture from the pump into the hot chamber 14 and the heated generated gas to flow from the chamber 15. This will cause the chamber 14 to contract and the chamber 15 to expand with the movable heat exchangers shifting to permit such changes.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. In an endothermic gas generator comprising a heating chamber, a gas generating unit enclosed in and separate from said heating chamber for generating a special gaseous atmosphere, means for supplying a gas mixture to said generating means, and reversing valve means for reversing the flow of gas in said generating means, the improvement wherein the gas generating means comprises a U-shaped catalytic chamber of substantially uniform cross section supported by the bottom of the U and having the free ends of the sides of the U connected to said valve means whereby a substantially uniform flow of gas through the chamber in either direction is obtained.

2. In an endothermic gas generator comprising a heating chamber, a gas generating unit enclosed in and separate from said heating chamber for generating a special gaseous atmosphere, means for supplying a gas mixture to said generating means, and reversing valve means for reversing the flow of gas in said generating means, the improvement wherein the gas generating means comprises a U-shaped catalytic chamber supported in the chamber by the bottom of the U and having the free ends of the sides of the U connected to said valve means through a flexible connector whereby free ends of the catalytic chamber can move independently to contract or expand in response to the temperature of the gas passing therethrough.

3. In an endothermic gas generator comprising a heating chamber, a gas generating unit enclosed in and separate from said heating chamber for generating a special gaseous atmosphere, means for supplying a gas mixture to said generating means, and reversing valve means for reversing the flow of gas in said generating means, the improvement wherein the gas generating means comprises a U-shaped catalytic chamber of uniform cross section supported in the chamber by the bottom of the U and having the free ends of the sides of the U each connected to said valve means through a heat exchanger unit disposed outside the heating chamber and forming a flexible connector whereby free ends of the catalytic chamber can move independentlyito contract or expand in response to the temperature of the gas passing therethrough.

4. In an endothermic gas generator comprising a heating chamber, a gas generating unit enclosed in and separate from said heating chamber for generating a special gaseous atmosphere, means for supplying a gas mixture to said generating means, and reversing valve means for reversing the flow of gas in said generating means, the improvement wherein the gas generating means comprises a U-shaped catalytic chamber of uniform cross section supported in the chamber by the bottom of the U and having the free ends of each of the sides of the U rigidly connected to a movable heat exchanger unit, said heat exchanger unit being disposed outside the heating chamber and connected to said valve means through a flexible connector whereby free ends of the catalytic chamber and connected heat exchanger can move independently to permit the chamber to contract or expand in response to the temperature of the gas passing therethrough.

5. 'In an endothermic gas generator comprising a heating chamber, a gas generating unit enclosed in and separate from said heating chamber for generating a special gaseous atmosphere, means for supplying a gas mixture to said generating means, and reversing valve means for reversing the flow of gas in said generating means, the improvement wherein the gas generating means comprises a U-shaped catalytic chamber of uniform cross section supported in the chamber by the bottom of the U and having the free ends of each of the sides of the U rigidly connected to a coil disposed in a fixed heat exchanger disposed outside the heating chamber and with the other 15 end of the coil connected to said valve means, said coil forming a flexible connector whereby free ends of the catalytic chamber can move independently to contract or expand in response to the temperature of the gas passing therethrough.

References Cited by the Examiner UNITED STATES PATENTS 2,304,203 12/42 Pyzel et al. 2,802,725 8/57 Kappel 2 3--2-5 2 X MORRIS O. WOLK, Primary Examiner.

JAMES H. TAYMAN, JR., Examiner. 

1. IN AN ENDOTHERMIC GAS GENERATOR COMPRISING A HEATING CHAMBER, A GAS GENERATING UNIT ENCLOSED IN A SEPARATE FROM SAID HEATING CHAMBER FOR GENERATING A SPECIAL GASEOUS ATMOSPHERE, MEANS FOR SUPPLYING A GAS MIXTURE TO SAID GENERATING MEANS, AND REVERSING VALVE MEANS FOR REVERSING THE FLOW OF GAS IN SAID GENERATING MEANS, THE IMPROVEMENT WHEREIN THE GAS GENERATING MEANS COMPRISES A U-SHAPED CATALYTIC CHAMBER OF SUBSTANTIALLY UNIFORM CROSS SECTION SUPPORTED BY THE BOTTOM OF THE U AND HING THE FREE ENDS OF THE SIDES OF THE U CONNECTED TO SAID VALVE MEANS WHEREBY A SUBSTANTIALLY UNIFORM FLOW OF GAS THROUGH THE CHAMBER IN EITHER DIRECTION IS OBTAINED. 